FI96103B - Drill - Google Patents

Abstract

2.1. To produce drilled holes to a defined depth, drills can be used which have a depth stop on the shank. <??>2.2. To avoid damage to the wall surface when the depth stop bears against it, a depth stop with an elastic damping element is proposed. <IMAGE>

Description

96103 '5

Drill

borr

The invention relates to a drill according to the preamble of the main claim.

10 To make boreholes, the depth of which must be precise, a drill with a depth stop is used on the drill bit. A shaped shoulder can be used as a depth response, which, however, can cause damage to the wall area of the borehole when the impact drill is applied to the wall surface. To make drill holes with a rear-15 cut at the bottom of the borehole, a drill is preferably used, the drilling head of which has side cutting edges on the side of the shank. Such drills can be attached to impact drills and used to make a borehole and a back cut. The depth response protruding from the drill shank limits the penetration depth of the drill.

20 As a depth response, a shoulder formed on the arm can be used, which, however, can strike the wall surface and strike it and cause the borehole to rupture. In this case, it must be taken into account in particular that in connection with the wobble movement required to make a rear cut to the bottom of the borehole, the depth response is at the wall surface of the masonry, whereby a rigid depth response can damage the wall surface.

With regard to the prior art, reference is first made to DE-GM-8515960, which discloses a drill with a depth response formed as a damping element rigidly attached to the drill arm. Also in the prior art DK publication 159603 discloses a drill in which. a depth response is used as the pivot bearing. EP 0034658 also represents the prior art and discloses a drill with no damping element at all, whereby drilling is a considerable fish. The prior art also includes EP 0171830, which discloses a drill with a depth response rotating relative to the drill arm, but no damping element or bulge in the drill arm. Further, U.S. Pat. No. 2,700,905, which relates to the prior art, discloses a drill having a rather complex structure with a depth stop releasably attached to the drill arm. Finally, with reference to the prior art, reference is made to DE 3704491, which discloses a drilling tool in which a joint is arranged at the connection between the drilling machine and the drilling tool.

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The object of the invention is to provide a drill whose depth response does not cause damage to the area of the borehole opening and which avoids the disadvantages associated with previous solutions, in particular the low locking strength of the formed hole, inaccurate boreholes, etc.

This object is achieved by the features set out in the characterizing part of the main claim. When the depth response is provided with a flexible damping member, damage to the wall surface in the area of the borehole opening, which could be caused by a rigid drilling response, can be avoided.

15

In a preferred embodiment of the drill according to the invention, the depth stop has a flexible annular damping member, preferably made of polyurethane or similar plastic. When the depth response comes into contact with the wall surface, the damping member between the wall surface and the shoulder arranged on the drill arm 20 acts and dampens the impacts from the impact drill. In addition, the damping member is sufficiently flexible so that the depth response, especially during the wobble movement of the drill, is completely against the wall surface when making a rear-cut borehole. During the wobble movement: although the damping member deforms alternately flexibly according to the wobble movement, the contact surface of the depth response on the wall surface does not change its position. The advantages of the damping member are therefore that the wall surface is not damaged and that an optimal contact of the depth response is obtained on the wall surface for the preparation of the back section.

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There is a support disc between the damping member and the shoulder formed on the drill arm, which greatly reduces the friction between the rotating shoulder and the wall surface when in contact with the non-rotating damping member. The support disc can be formed as a metal disc or consist of a plastic with good sliding properties.

• 4 il i iä ·; g.i> i i, i m 3 96103

The damping member can be secured against axial displacement along the arm by a shoulder contact with the shoulder formed on the drill arm. The cover can completely surround the damping member or engage the cylindrical side wall of the damping member so that the lower area of the damping member 5, which forms the contact surface of the depth response, can come out freely in the direction of the drilling head. The latter embodiment has a soft contact surface like the embodiment without a cover, which especially saves the wall surface.

In contrast to the invention, the depth response could also be formed as a flexible, cup-shaped damping member, the side wall of which extends to the shoulder formed in the drill bit and has a through hole base through which the drill bit leading from the shoulder to the drilling head extends. The damping member can then be pushed in a simple manner through the drilling head up to the shoulder along the drill arm, whereby the side wall touching the shoulder of the damping member is pushed over the shoulder by means of a small pressure. The damping member can also be made of a flexible plastic, such as polyurethane, as a one-piece piece.

To reduce or avoid friction losses between the shoulder and the bottom of the damping member, a support disc arranged between the shoulder and the base in a space surrounded by the damping member may be inserted into the drill arm.

; The invention will now be described in more detail with reference to Figures 1-3 of the drawing, in which:

Fig. 1 is a first embodiment example of a drill provided with a damping member, Fig. 2 is a second embodiment example of a drill having a cover contacting the damping member,

Fig. 3 is a partially illustrated exemplary embodiment of a drill having a laterally engaging cover for the damping member, and · · 96103 '

Figure 4 further shows an example of a drill closely related to the invention, but not according to the invention, which has a depth response formed as a flexible, cup-shaped damping member.

The drill 1 shown in Fig. 1 has a shoulder 2 formed on the drill arm, which abuts the support disc 3. Below the support disc 3, a damping member 4, which is a disc made of flexible plastic, is arranged.

The drill 1 has side cutting edges 6,7 on the side of the drill shank, which act in a manner known per se to produce a rear section at the bottom of the drill hole. The drill shank has a protrusion 8 which defines a wobble point inside the drill hole when making the rear cut. The drill 1 is then at the widest point 9 15 of the protrusion 8 against the wall of the drill hole and can turn laterally around this wobble point.

The shoulder 2, the support disc 3 and the damping member 4 together form a depth response 10 which determines the maximum penetration depth 20 of the drill 1 into the masonry. When the damping member 4 abuts its contact surface 11 with the wall surface 12 of the masonry 13, the drill 1 fixed to the impact drill in a manner not shown can be rotated laterally to form a rear section 14 at the bottom of the borehole. The shoulder 2 bends alternately laterally due to the swinging movement, whereby the damper-25 member 4 deforms slightly flexibly. The damping member 4 is then completely confined in its contact surface 11 to the wall surface 12.

The drill 1 shown in Fig. 2 has a depth stop 2 consisting of a shoulder 2, a support disc 3, a damping member 4 and a cover 15 contacting the damping member 30 4 and the shoulder 2. The cover 15 has an upper • hole 16 and a lower hole 17 and is otherwise closed on all sides t.

In Fig. 3, the depth stop 10 also has a cover 18, the lower edge 19 35 of which folds inwards and engages laterally in the cylindrical side wall of the damping member 4.

• · 5 96103

The support disc 3 is a metal disc, but a plastic disc made of plastic with good sliding properties can also be used.

The drill 1 shown in Fig. 4 has, as a depth response 10, a flexible, cup-shaped damping member 20 and a shoulder 21 formed in the drill shank 21. In the space between the base 22 and the shoulder 21 of the damping member 20 there is a support disc 23 which may be made of metal or plastic with good sliding properties. The damping member 20 is made of 10 flexible plastics in one piece, slightly frustoconical.

The floor 22 of the damping member 20 has a through hole 24 through which the drill shank and its drilling powder grooves 25 and drilling head 26 extend. The Si-15 wall 25 tapers upward like the circumferential surface of the shoulder 21. The conical circumferential surface of the shoulder 21 has a similar inclination as the conical inner surface of the side wall 27 of the damping member 20.

The drill 1 shown can be attached from the top of the shaft to an impact drill 20 or the like not shown. The impacts transmitted to the drill shank of the impact drill are damped so strongly when the damping member 20 contacts the wall surface that damage to the wall surface from the mouth area of the borehole can be reliably avoided.

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Claims (4)

96103 A drill for making boreholes with a rear cut for masonry, the drill end (5) of the drill (1) having side cutting edges (6,7) projecting outwards from the drill shank to the side 5 and a shoulder flange (2) on which a freely rotatable annular damping element (4) is arranged. depth stop (10), characterized in that the drill arm is formed between the drilling head (5) and the depth stop (10) by a bulging (8) extending towards the drilling head (5) and the depth stop (10) to form a pivot bearing, the damping element (4) rests against a plate-shaped metal ring (3) which rests against an Ola coil flange (2) formed in one piece on the drill arm. Drill according to Claim 1, characterized in that a cover (15, 18) which contacts the shoulder (2) is connected to the damping element (4). Drill according to Claim 2, characterized in that the cover (15) encloses the damping element (4) and the shoulder (2). Drill according to Claim 2, characterized in that the cover (18) engages laterally in the damping element (4) so that the lower part of the damping element (4) extending in the direction of the drilling head protrudes freely from the cover (18). 30 il; m i im ma i 96103